Determining how much antifouling you will need is fairly simple. You can calculate the area to paint by multiplying the length of your hull (LOA) by the beam and multiply by 0.85 (LOA x B x 0.85 = Area). Then divide the area by the coverage of the paint you've chosen to determine how many quarts per coat you will need.

Refer to the reference chart below for another quick estimate of how much antifouling paint is required for two coats.